Well liquid removal device

ABSTRACT

A device for removing liquid from a well bore which utilizes two valve means. One valve admits liquid to the tubing and the other valve admits gas to the tubing to lift liquid in the tubing to the earth&#39;&#39;s surface.

United States Patent Inventor Appl. No.

Filed Patented Assignee Bobby L. Douglas Ennis, Tex.

Sept. 1 1, 1969 May 25, 1971 Dresser Industries, Inc. Dallas, Tex.

WELL LIQUID REMOVAL DEVICE 8 Claims, 1 Drawing Fig.

US. Cl 166/224, 103/232 Int. Cl E2lb 33/00 Field of Search 166/224,

[56] References Cited UNITED STATES PATENTS 2.994336 8/1961 Bryan 103/232 3,213,806 10/1965 Walton 103/232 3,385,227 5/1968 Hart, Jr. 103/232 Primary Examiner-James A. Leppink Attorneys-Robert W. Mayer, Thomas P. Hubbard, Jr., Daniel Rubin, Raymond T. Majesko, Roy L. Van Winkle, William E. Johnson, Jr., Roderick W. MacDonald and Eddie E. Scott ABSTRACT: A device for removing liquid from a well bore which utilizes two valve means. One valve admits liquid to the tubing and the other valve admits gas to the tubing to lift liquid in the tubing to the earths surface.

PATENTEU MAY2'5 IQTI T Miam w\ m J 7 6 O 4 L 5131:; Q MEWS w 3 22 v m T 0 :;m ME l== INVENTOR BOBBY L. DOUGLAS WWW ATTORNEY WELL LIQUID REMOVAL DEVICE BACKGROUND OF THE INVENTION In gas wells, gas issuing from underground strata into the borehole of the well usually carries along some liquid which is water, oil, and the like. This liquid collects in the bottom of the well bore and can eventually buildup to a height where it substantially cuts off the flow of gas from the strata into the well bore thereby severely reducing or even completely stopping gas production from that well. In such a situation the liquid has to be removed in order to continue optimum production of the gas well.

Therefore, it is very desirable to have a device in the gas well which will automatically remove liquid therefrom when a predetermined maximum amount of liquid has collected. This prevents the liquid from building up in the well to a height where it interferes with the production of the well in any manner.

SUMMARY OF THE INVENTION According to this invention there is provided a device for removing liquid from a well bore comprising a chamber having a first inlet means and a first outlet means, a first valve means for regulating fluid flow therebetween, a second inlet means and second outlet means, and a second valve means for regulating fluid flow therebetween. The first inlet and first outlet means are for admitting liquid from the well bore to the interior of the well tubing and the second inlet and second outlet means are for admitting gas to the interior of the tubing to lift liquid upwardly therein.

This invention also relates to the combination of the abovedescribed device with at least one section of well tubing, the first and second outlet means being adapted to communicate with the interior of the tubing while the first and second inlet means communicate with the atmosphere surrounding the exterior of the tubing in the well bore.

This invention is useful in all types of wells and in any other situation wherein liquid must be separated from gas and the liquid removed separately from the gas in a remote location and under automatic operation. Thus, the term well bore in this invention should be construed broadly to any remote location containing liquid from which it is desirable to remove the liquid. This invention is particularly applicable to producing gas wells which tend to collect a large amount of liquid in the bottom of the borehole but is applicable to all other types of wells wherein a similar situation obtains.

Accordingly, it is an object of this invention to provide a new and improved device for removing liquid from a well bore. It is another object to provide a new and improved combination of well tubing and a device for removing liquid from a well bore into the tubing and then out through the tubing. It is DETAILED DESCRIPTION OF THE INVENTION The drawing shows apparatus embodying this inventionv More specifically, the drawing shows the lower end of a well bore 1 which is bottomed in the earth at 2 and lined with casing 3. Casing 3 contains perforations 4 so that the interior of the well bore and casing 3 is in open communication with a gas and liquid producing geologic strata 5.

Well tubing 6 extends the length of well bore 1 from the earths surface down to the vicinity of the producing strata 5 and is closed at its bottom 7.

Tubing 6 carries a device 10 according to this invention which is composed of housing 11. Housing 11 contains an elongate, hollow chamber 12 which has a first inlet means 13 at the bottom end thereof and a first outlet means 14 which is separate from, spaced from, but yet near inlet means 13.

First inlet and outlet means 13 and 14 have associated therewith valve means 15 which contains base 16, which slidingly and sealingly engages the interior walls of chamber 12 by means of O-ring 17, valve stem 18 depending from base 16, and valve member IQ which seats on first inlet means 13 to close same and thereby regulate fluid flow between inlet 13 and outlet 14. Valve means 15 is biased by means of spring 20, which is compressed between base 16 and annular flange 21, to normally force valve member 19 to seat against inlet 13 thereby closing same.

Chamber 12 also contains second inlet means 25 and second outlet means 26 which are also separate and spaced from one another. First inlet and outlet means 13 and 14 are in a separate portion of chamber 13 from that portion which contains second inlet and outlet means 25 and 26. For exam ple, first inlet and outlet means 13 and 14 can be in about the bottom half of chamber 12 while second inlet and outlet means 25 and 26 can be in about the upper half of chamber 12.

Second outlet means 26 carries a conventional gas lift device 27 which is a valve means that normally closes second outlet means 26 and that opens in response to pressure on the interior of tubing 6 acting in second outlet means 26. Second inlet means 25 is shaped so as not to allow liquid, suspended in gas, passing upwardly in well bore 1 as indicated by arrow 28 to enter chamber 12 unless valve means 27 is open. Valve means 27 therefore regulates the flow of gas between second inlet and second outlet means 25 and 26.

In operation, liquid passing through perforations 4 with the gas falls to the bottom of the borehole as indicated by arrow 29 and collects therein as a body of liquid 30. The liquid level of liquid body 30 will increase in borehole 1 up to and beyond perforations 4 if not removed thereby causing a hydrostatic back pressure through perforations 4 which diminishes or even stops gas flow from strata 5 through perforations 4 and up well bore I.

The apparatus of this invention prevents the liquid level of liquid body 30 from reaching perforations 4 because the force of spring 20 is set so that when the liquid level reaches a height approaching perforations 4 the hydrostatic head from this height of liquid acting across the area of inlet means 13 is sufficient to overcome the force of spring 20 and push valve head 19 away from inlet means 13. This then opens communication between inlet means 13 and outlet means 14 so that liquid 30 can pass, due to its own hydrostatic trend, into the interior of tubing 6 forming a body of liquid 31 in the lower end of tubing 6. For example, spring 20 can have a force set at about 5 pounds per square inch of liquid effect from body 30. Base 16 in inlet mean 13 can have approximately equal cross-sectional areas. When the body of liquid 30 builds up to a height in well bore 1 to produce a head pressure acting across inlet means 13 equal to about 5 p.s.i., valve means 15 will open and some of liquid 30 will flow into the interior of tubing 6. When sufficient of liquid 30 has passed into tubing 6 to reduce the head pressure of body 30 to less than 5 psi. spring 20 will again force valve member 19 into seating engagement with inlet means 13 thereby cutting off the flow of liquid from inlet 13 to outlet 14.

The cross-sectional area sizes of the various inlet and outlet means can be varied as desired and as obvious to those skilled in the art. For example, outlet means 14 can have a smaller cross-sectional area than that of inlet means 13 for a choke effect or outlet 14 can have a larger area if it is desired for valve means to snap shut rather than gradually close. Similar considerations apply to inlet and outlet means 25 and 26.

When the body of liquid 31 reaches a height in tubing 6 sufficient to overcome the closing pressure in valve means 27, valve means 27 is opened in substantially the same manner as discussed hereinabove with regard to valve means 15. When valve means 27 is open, gas passes through inlet means 25 into chamber 12, through valve means 27 into outlet means 26 and into the interior of tubing 6. The gas then rises in the interior of tubing 6 carrying before it a portion of liquid from body 31 which is substantially equal to that portion of liquid which extends above outlet means 26. Conventional valve means can be employed for valve means 27. In addition to valve means such as that shown for valve means 15, valve means 27 can employ conventional gas lift valves which are commercially available and well known in the art. For example, gas lift valves which are actuated (opened) primarily by tubing pressure include Guiberson gas lift valves types MF-77, MWF77, MF-3l, MWF-Bl, and MWAF-3l, all of which are commer cially available.

It can be seen from the above that as greater and greater amounts of liquid collect in the bottom of the well bore, greater and greater amounts of liquid are passed from the well bore into the interior of tubing 6. When the collection of liquid in tubing 6 reaches a sufficiently large amount, valve 27 opens and gas is passed into tubing 6 to lift a portion of the liquid therein upwardly, e.g., to the earths surface. All these operations are done automatically as needed depending upon how much liquid passes through perforations 4 and collects in the bottom of the well bore. Thus, perforations 4 are always kept clear of liquid and optimum gas producing conditions in the well bore are constantly maintained as far as the liquid that collects in the bottom of the well bore is concerned.

The device of this invention can be made as a separate piece which can be attached to a section of tubing or can be made as a one piece combination of a section of tubing and the device as shown in the drawing.

If desired, valve means can be employed to close first outlet 14 instead of first inlet 13 and/or second inlet 25 instead of second outlet 26 so long as the above-described results of operation of the device of this invention are achieved.

Reasonable variations and modifications are possible within the scope of this disclosure without departing from the spirit and scope of this invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

I claim: I

l. A device for removing liquid from a well bore comprisa chamber having first and second inlet means and first and second outlet means,

a first valve means carried by said chamber for regulating liquid flow between said first inlet means and said first outlet means, and

a second valve means carried by said chamber for regulating gas flow between said second inlet means and said second outlet means.

2. The device according to claim 1 wherein said chamber is adapted to be mounted on a section of well tubing so that said first and second outlet means communicate with the interior of said tubing and said first and second inlet means communicate with the exterior of said tubing.

3. The device according to claim 1 wherein said first inlet means and first outlet means are near but spaced from one another in one portion of said chamber and said second inlet means and second outlet means are near but spaced from one another in a different portion of saidchamber.

4. The device according to claim 1 wherein said first valve means prevents communication between (1-) either of said first inlet means or first outlet means and (2) either of said second inlet means or second outlet means, said first valve means is biased to normally close said first inlet means to prevent communication between said first inlet means and said first outlet means, said first valve means opens said first inlet means when a predetermined pressure is reached in said first inlet means, said second valve means is biased to normally close said second outlet means to prevent communication between said second inlet means and said second outlet means, and said second valve means opens said second outlet means when a predetermined pressure is reached in said second outlet means.

5. The device according to claim 4 wherein said second valve means is a gas lift valve means that is activated by well tubing ipressure.

6. e device according to claim 1 wherein said device IS mounted on well tubing so that said first and second outlet means communicate with the interior of said tubing and said first and second inlet means communicate with the atmosphere exterior to said tubing.

7. The device according to claim 1 wherein said chamber is an elongate, hollow member having said first inlet means and first outlet means spaced apart but in one end of said chamber and said second inlet means and second outlet means spaced apart but in about the opposite end of said chamber, said chamber carries said first valve means on the interior thereof and spring biased to normally seat on and close said first inlet means so that fluid cannot pass into said first inlet means and out said second inlet means, said first valve means physically separates the end of said chamber which contains said first inlet means and first outlet means from the end of said chamber which contains said second inlet means and second outlet means, said second valve means is a gas lift valve means carried internally at said chamber and biased to normally close said second outlet means so that fluid cannot pass into said second inlet means and out said second outlet means until the pressure in said second outlet means reaches a predeter mined value.

8. The device according to claim 7 wherein said device is carried on well tubing so that said first and second outlet means communicate with the interior of said tubing and said first and second inlet means communicate with the atmosphere surrounding the exterior of said tubing, said second inlet and outlet means being vertically elevated above said first inlet and outlet means when said tubing is upright in the position in which it is used in operation. 

2. The device according to claim 1 wherein said chamber is adapted to be mounted on a section of well tubing so that said first and second outlet means communicate with the interior of said tubing and said first and second inlet means communicate with the exterior of said tubing.
 3. The device according to claim 1 wherein said first inlet means and first outlet means are near but spaced from one another in one portion of said chamber and said seCond inlet means and second outlet means are near but spaced from one another in a different portion of said chamber.
 4. The device according to claim 1 wherein said first valve means prevents communication between (1) either of said first inlet means or first outlet means and (2) either of said second inlet means or second outlet means, said first valve means is biased to normally close said first inlet means to prevent communication between said first inlet means and said first outlet means, said first valve means opens said first inlet means when a predetermined pressure is reached in said first inlet means, said second valve means is biased to normally close said second outlet means to prevent communication between said second inlet means and said second outlet means, and said second valve means opens said second outlet means when a predetermined pressure is reached in said second outlet means.
 5. The device according to claim 4 wherein said second valve means is a gas lift valve means that is activated by well tubing pressure.
 6. The device according to claim 1 wherein said device is mounted on well tubing so that said first and second outlet means communicate with the interior of said tubing and said first and second inlet means communicate with the atmosphere exterior to said tubing.
 7. The device according to claim 1 wherein said chamber is an elongate, hollow member having said first inlet means and first outlet means spaced apart but in one end of said chamber and said second inlet means and second outlet means spaced apart but in about the opposite end of said chamber, said chamber carries said first valve means on the interior thereof and spring biased to normally seat on and close said first inlet means so that fluid cannot pass into said first inlet means and out said second inlet means, said first valve means physically separates the end of said chamber which contains said first inlet means and first outlet means from the end of said chamber which contains said second inlet means and second outlet means, said second valve means is a gas lift valve means carried internally at said chamber and biased to normally close said second outlet means so that fluid cannot pass into said second inlet means and out said second outlet means until the pressure in said second outlet means reaches a predetermined value.
 8. The device according to claim 7 wherein said device is carried on well tubing so that said first and second outlet means communicate with the interior of said tubing and said first and second inlet means communicate with the atmosphere surrounding the exterior of said tubing, said second inlet and outlet means being vertically elevated above said first inlet and outlet means when said tubing is upright in the position in which it is used in operation. 